Method for producing a refractory material based on magnesia or magnesia spinel, and refractory material based on magnesia or magnesia spinel

Abstract

The invention relates to a method for producing a refractory material based on magnesia or magnesia spinel, and to a refractory material based on magnesia or magnesia spinel.

The invention claimed is: 
     
       1. A method for producing a refractory material based on magnesia or magnesia spinel with the following steps:
 1.1 provision of a batch comprising
 1.1.1 a first component made of at least one of the following materials: 
 magnesia or magnesia spinel; 
 1.1.2 a second component comprising substances by means of which a binding phase comprising an AlN polytypoid can be formed when temperature is applied; 
 1.1.3 wherein the mean grain size of the first component is greater than the mean grain size of the second component; 
 
 1.2 application of temperature to the batch within a temperature range in which the second component forms a binding phase comprising an AlN polytypoid; 
 1.3 the batch is exposed to pressure during the application of temperature in this temperature range. 
 
     
     
       2. The method according to  claim 1 , wherein the batch is exposed to a pressure of over 1 MPa. 
     
     
       3. The method according to  claim 1 , wherein the batch is exposed to a temperature of at least 1200° C. 
     
     
       4. The method according to  claim 1 , wherein the second component comprises substances by means of which a binding phase can be formed when temperature is applied, which binding phase comprises one of the following AlN polytypoids: MgAlON polytypoid or MgSiAlON—AlN polytypoid. 
     
     
       5. The method according to  claim 1 , wherein the components of the batch exhibit the following fractions by mass, relative to the total mass of the batch:
 First component: 95 to 50% by mass; 
 Second component: 5 to 50% by mass. 
 
     
     
       6. The method according to  claim 1 , wherein at least 90% by mass of the second component exhibits a grain size of under 63 μm. 
     
     
       7. The method according to  claim 1 , wherein at least 90% by mass of the first component exhibits a grain size of over 63 μm. 
     
     
       8. A refractory material based on magnesia or magnesia spinel produced by the following steps:
 producing a batch comprising,
 a first component made of at least one of the following materials:
 magnesia or magnesia spinel; 
 
 a second component comprising substances by means of which a binding phase comprising an AlN polytypoid can be formed when temperature is applied; 
 
 applying a temperature to the batch within a temperature range in which the second component forms a binding phase comprising an AlN polytypoid; wherein the mean grain size of the first component is greater than the mean grain size of the second component; 
 exposing the batch to pressure during the application of temperature in the temperature range; 
 wherein the structure whereof is made up of grains comprising at least one of the following substances: magnesia or magnesia spinel, 
 wherein the grains are surrounded by a binding phase which comprises an AlN polytypoid. 
 
     
     
       9. The refractory material according to  claim 8  having a mass fraction of grains within the range of 95-50% by mass and a fraction of binding phase within the range of 5-50% by mass relative to the material in each case. 
     
     
       10. The refractory material according to  claim 8  having a fraction of MgSiAlON polytypoid in the binding phase within the range of 30-100% by mass or having a fraction of MgAlON polytypoid in the binding phase within the range of 10-100% by mass, relative to the binding phase in each case. 
     
     
       11. The refractory material according to  claim 8  having a cold compression resistance of at least 40 MPa. 
     
     
       12. The refractory material according to  claim 8  having a modulus of elasticity of no more than 80 GPa. 
     
     
       13. The refractory material according to  claim 8  having a gross density of at least 2.80 g/cm 3 . 
     
     
       14. The refractory material according to  claim 8  having an open porosity of no more than 20%.